Scientists have found a new way to overcome one of the biggest obstacles to the use of viruses for therapeutic genes.

Scientists from the Institute for research at national level have found a way to overcome one of the biggest obstacles to the use of viruses for administration of therapeutic genes, that is, how to prevent the immune system to neutralize the virus before it has delivered its genetic set.

Gene therapy is one of the most promising possibilities for the treatment of genetic disorders such as muscular dystrophy, congenital blindness and hemophilia. Scientists explore gene therapy as a cure for certain types of cancer, neurodegenerative diseases, viral infections and other acquired diseases. In order to obtain a therapeutic gene into cells, scientists use viruses that deliver its genetic material in cells as part of their normal replication process.

Again and again, these efforts were thwarted by the very immune system of the body that damages each viral vector. Thus the therapeutic gene can be delivered to diseased cells and disease raging in full force.

A team led by Louis-Rodino Klapak, PhD, and Jerry Mendel, MD, principal investigator in the Center for Gene Therapy at Nationwide, show for the first time that using a process called plasmapheresis, just before delivery of the virus for gene therapy he is protected long enough to enter the cell and deliver their genetic material.

In a study of gene therapy for the treatment of Duchenne muscular dystrophy (DMD), Dr. Rodino-Klapak using plasmapheresis in a large animal model, and then injected a virus carrying the gene micro-dystrophin. When studying the level of gene expression of the micro-dystrophin in animals, it was found that there is a 500% increase in the gene expression in the animals who received a plasmapheresis.

Dr. Mendel believes that right now, gene therapy seems to work best in patients who have antibodies to the virus. It is this virus is used to supply the necessary gene. It is exactly this gene, which is a therapeutic, curative intent of the organism suffering from a disease. On the other hand, it limits the number of patients who can benefit from gene therapy. This is because in very few patients lacking antibodies against the virus.

Using the method of plasmapheresis repeatedly increases the potential of gene therapy, as this eliminates the obstacle called immune response of the organism.

As gene therapy becomes more widespread, it may be necessary, patients receiving more than one course of treatment.

The main problem is that when you go home after the first treatment, their body develops antibodies to the virus used to deliver the therapeutic gene. The use of plasma in a patient who previously received gene therapy may allow him to be treated again.

It was developed by scientists from London and will be used in addition to conventional treatment methods. By her doctors of stem cells from the bone marrow of the patient, which will then be injected into the damaged heart.

It is believed that they release the chemical signals that increase activity of the stem cells of the heart. The therapy is used mainly for the treatment of chronic heart failure and coronary artery disease .

So far, the experiments offer hope that this technique znaitelno reduce deaths from heart trouble .

Cardiovascular disease affects many people , the age limit drops more and more . They are the leading cause of death globally.

According to the World Health Organization cardiovascular disease die each year over 17 million people. This equates to 30% of global deaths a year. Of these, nearly 7 million were due to coronary heart disease, and about 9 million deaths are related in one way or another with high blood pressure.

WHO forecasts are cardiovascular diseases remain the leading cause of mortality in the coming decades. Expected mortality of them exceeded 23 million a year by 2030

Implementation of the type of treatment , including stem cells would improve and prolong the lives of patients with a heart condition .

Scientists have corrected the genetic fault that causes Down's syndrome– albeit in isolated cells – raising the prospect of a radical therapy for the disorder.

In an elegant series of experiments, US researchers took cells from people with DS and silenced the extra chromosome that causes the condition. A treatment based on the work remains a distant hope, but scientists in the field said the feat was the first major step towards a "chromosome therapy" for Down's syndrome.

"This is a real technical breakthrough. It opens up whole new avenues of research," said Elizabeth Fisher, professor of neurogenetics at UCL, who was not involved in the study. "This is really the first sniff we've had of anything to do with gene therapy for Down's syndrome."

Around 750 babies are born with DS in Britain each year while globally between one in a 1000 and one in 1100 births are DS babies. Most experience learning difficulties.

Despite advances in medical care that allow most to live well into middle age, those who have the disorder are at risk of heart defects, bowel and blood disorders, and thyroid problems.

Though a full treatment is still many years off, the work will drive the search for therapies that improve common symptoms of DS, from immune and gastrointestinal problems, to childhood leukaemia and early-onset dementia.

"This will accelerate our understanding of the cellular defects in Down's syndrome and whether they can be treated with certain drugs," said Jeanne Lawrence, who led the team at the University of Massachusetts.

"The long-range possibility – and it's an uncertain possibility – is a chromosome therapy for Down's syndrome. But that is 10 years or more away. I don't want to get people's hopes up."

In a healthy person, almost every cell in the body carries 23 pairs of chromosomes, which hold nearly all of the genes needed for human life. But glitches in the early embryo can sometimes leave babies with too many chromosomes. Down's syndrome arises when cells have an extra copy of chromosome 21.

Lawrence's team used "genome editing", a procedure that allows DNA to be cut and pasted, to drop a gene called XIST into the extra chromosome in cells taken from people with Down's syndrome.

Once in place, the gene caused a buildup of a version of a molecule called RNA, which coated the extra chromosome and ultimately shut it down.

Previous studies found that the XIST gene is crucial for normal human development. Sex is determined by the combination of X and Y chromosomes a person inherits: men are XY, and women are XX. TheXIST gene sits on the X chromosome, but is only active in women. When it switches on, it silences the second X chromosome.

Lawrence's work shows that the gene can shut down other chromosomes too, a finding that paves the way for treating a range of other "trisomy" disorders, such as Edward syndrome and Patau syndrome, caused by extra copies of chromosomes 18 and 13 respectively.

Writing in the journal Nature, the team describes how cells corrected for an extra chromosome 21 grew better, and developed more swiftly into early-stage brain cells. The work, the researchers write, "surmounts the major first step towards potential development of chromosome therapy".

The work is already helping scientists to tease apart how an extra chromosome 21 causes a raft of problems that strike people with Down's syndrome at various ages. "By the time people with Down's syndrome are in their 60s, about 60% will succumb to dementia. One question is, if we could turn off the extra chromosome in adults, would that stop or ameliorate their dementia?" said Fisher. Another approach would cut the risk of leukaemia by silencing the extra chromosome in bone marrow cells.

The US team has already begun work that aims to prevent Down's syndrome in mice, by silencing the extra chromosome 21 in early-stage embryos. "That would correct the whole mouse, but it's not really practical in humans," said Lawrence.

A chromosome therapy for humans would be fraught with practical and ethical difficulties. To prevent Down's syndrome, the genome editing would have to be performed on an embryo or foetus in the womb, and correct most, if not all, of the future child's cells. That is far beyond what is possible, or allowed, today.

WITHIN just eight days of starting a novel gene therapy, David Aponte's "incurable" leukaemia had vanished. For four other patients, the same happened within eight weeks, although one later died from a blood clot unrelated to the treatment, and another after relapsing. The cured trio, who were all previously diagnosed with usually fatal relapses of acute lymphoblastic leukaemia, have now been in remission for between 5 months and 2 years. Michel Sadelain of the Memorial Sloan-Kettering Cancer Center in New York, co-leader of the group that designed the trial, says that a second trial of 50 patients is being readied, and the team is looking into using the technique to treat other cancers.

The key to the new therapy is identifying a molecule unique to the surface of cancer cells, then genetically engineering a patient's immune cells to attack it. In acute lymphoblastic leukaemia, immune cells called B-cells become malignant. The team were able to target a surface molecule known as CD19 that is only present on B-cells. Doctors extracted other immune cells called T-cells from the patients. These were treated with a harmless virus, which installed a new gene redirecting them to attack all cells bearing CD19. When the engineered T-cells were reinfused into the patients, they rapidly killed all B-cells, cancerous or otherwise.

"The stunning finding was that in all five patients, tumours were undetectable after the treatment," says Sadelain. He reckons that the body should replenish the immune system with regular T-cells and healthy B-cells after a couple of months. However, the patients received donated bone marrow to ensure they could regrow a healthy immune system.

The treatment is not the first to re-engineer T-cells to attack a form of leukaemia. Last year, an international company called Adaptimmune used the approach to treat 13 people with multiple myeloma – it left 10 in remission. "Although it's early days for these trials, the approach of modifying a patient's T-cells to attack their cancer is looking increasingly like one that will, in time, have a place alongside more traditional treatments," says Paul Moss of Cancer Research UK. Sadelain's team is now investigating the scope for attacking other cancers. Where no single surface molecule is unique to a cancer, he is seeking to target pairs of molecules that only occur together on cancer cells. In January, he demonstrated this approach by wiping out human prostate tumours implanted in mice, using T-cells engineered to target two surface molecules.